Process for the improvement of the properties of artificial masses and fibers manufactured from proteinlike substances



Patented Feb. 6, 1945 PROCESS FOR THE IIHPROVEMENT OF THE PROPERTIES OF ARTIFICIAL MASSES AND FIBERS MANUFACT LIKE SUBSTANCES URED FROM PROTEIN Walter Friedrich Tschudin, Basel, Switzerland,

assignor to firm of Sandoz A. G., Basel, Switzerland 7 No Drawing. Application November 6, 1939, Se-

iiglgNo. 303,128. In Switzerland January 27, 3

7 Claims.

The present invention relates to a process for improving the dynamometric resistance and the stability to heat, to boiling water, to dyeing and other treatments of artificial masses and fibers prepared from protein-like substances.

The present invention is an improvement and development of the invention described in the copending application Ser. No. 303,158 filed at the same date as the present patent application by Giampiero Comolli, and also assigned to the,

firm of Sandoz A. G.

It has been found that artificial masses and artificial fibers which have been prepared from albuminic or proteinic substances, like albumin, casein, gelatine, keratin, glue and the like, can be greatly improved in their properties when they are subjected to a tanning operation at a temperature above 50 C. with compounds of trivalent chromium, and eventually to a subsequent treatment with acid binding agents.

By the above treatment the formation and the fixation of water insoluble chrome compounds takes place in and on the treated material, whereoy its resistance towards boiling water, even in presence of organic and inorganic acids, is greatly improved. This improvement is especially re markable in the case of artificial fibers prepared from casein and known for instance under the trade-mark Lanital. Lanital, which has been tanned with chrome compounds according to the present process, can be dyed by the usual dyeing processes without decreasing the dynamometric resistance and other properties of the material.

Appropriate dyestufis are, besides the substantive and the sulphur dyestufis, acid and chrome dyestufis, which require; in order to be fixed on the fiber, the dyeing at the boiling temperature in presence of acid. The dyeings obtained on Lanital treated according to the present invention possess a much better looking and a smoother touch. They'also possess better fastness properties than on untreated Lanital insofar, as they withstand a washing with soap'and soda at 60 C. and even the milling, if the dyeing has been carried out with chrome dyestufis.-

A further important improvement resides in that the treated fibers possess in wet and in dry" form a much higher mechanical resistance and elasticity in comparison with the untreated fibers. The treated fibers possess also a better resistance to wear and withstand the milling much better than untreated Lanital.

For carrying out the present invention all compounds of trivalent chromium can be used,

but it is preferable to use such derivatives that are rapidly taken up. by the fiber. The rapidity of the taking up of the chromium derivative depends on the sort of the chromium-compound and the temperature at which the operation is carried out. By suitable additions the operation can be made more rapid or slower; generally an addition of acid makes it more rapid, whereas the addition of salts or the use of basic chromium compounds makes it slower. v

It is natural that the action of the tanning is the best, when the same. has been carried out levelly; therefore it is necessary to soak. the.

material in the solution. of the chrome compound as well as possible. For this purpose several mechanical means can be used. Sometimes it is also preferable to add wetting and penetrating agents that are active inthe presence of chromium compounds.

For carrying out the present process salts of the trivalent chromium with in-organic or organic acids and also double salts and complex salts like chrome chloride, chrome fiuoride,;

generally carried out in an aqueous medium,

whereby water soluble chromium salts are used.

But the process is not limited to the use of aqueous baths, as the water can be replaced completely or partially by other solvents which do not dissolve the artificial material.

In order to obtain a good result it is preferable to use the chromium compounds in concentratedsolution and in an excess. One must not, thereforaas in themordanting of woolrwith chromium compounds, use only a small percentage thereof caiculated on the weight of material to be treated. It is necessary to use from the beginning great quantities of the chrome compounds.- The time of the treatment varies in wide limits and can be seen from the following examples; it is dependent from the sort of the, material to be treated, from its form, from temperature and from the reactivity of the selected chrome compound. After the treatment,

the chrome compound which has not been utilized is separated from the material in any suitable way, for instance by pressing out, hydroextracting etc., and the treatedmaterial is carefully washed out with water. The regenerated solutions of the chromium salts can, after standardisation be used for the treatment of new lots of material.v

The tanned wet material does not change on storing in wet form. If one will dye it with such dyestuffs that use acid for the dyeing, it can be dyed directly. If it is intended to dye it in a neutral or alkaline bath, it is preferable to treat the tanned material with acid binding agents like soda or ammonia in order to neutralize the small quantities of acids contained therein.

In a similar way as with manufactured masses and fibers the present tanning process can also be carried out during the manufacture of the artificial products.- v

In some cases it is possible to carry out the tanning operation simultaneously with the dyeing of the fibers, for instance, when the artificial fibers are intended to be dyed with mordant dyestuffs in presence of salts of trivalent chromium and in one bath. In this case the quantity of the chromium salt must be strongly increased in order that the artificial fiber becomes tanned and the chromium lake of the dyestufi becomes aproduced.

The following examples, without being limitative, show how the present invention can be carried out.

Example 1 10 parts of the artificial fiber known under the trade name Lanital are treated during 5 minutes at 60 C. with a solution of parts of chrome alum in 100 parts of water, hydroextracted, then washed with cold water, treated during 1 minute with per cent ammonia solution, washed again, hydroextracted and dried. The Lanital treated in this manner is colored in a clear green, possesses a high lustre and a smooth touch. By dyeing in a boiling bath in presence oi sulphuric acid, the breakage resistance of the fiber is only slightly decreased and is much better than the resistance of the nontanned Lanital treated with the same acid bath.

Example 2 Lanital yarn is treated during 30 minutes at boiling temperature in an aqueous 10 per cent chrome alum solution in a bath ratio 1:10, hydroextracted, well washed with cold water, then with water containing ammonia, then with fresh water and dried. The touch of the greenish dyed Lanital is smooth and its resistance against hot diluted acids and alkaliesis excellent. The above cited properties remain unaltered when the material is subjected to a dyeing operation. The tanned green Lanital is fast to storing i wet and dry condition.

If the tanning is carried out with the above said chrome alum solution under addition of 2% of sulphuric acid, calculated on the weight of the dry Lanital, the tanning is finished already after 10 minutes. After hydroextracting and washing, it is absolutely necessary to treat itin a bath containing an acid binding agent in order to neutralize the acid remaining in the fiber and which otherwise would destroy the material on drying.

Example 3 Lanital yarn, is treated with 35% of chrome alum, calculated on the weight of the dry Lanital, in an aqueous bath during 30 minutes at C., whereby the Lanital becomes colored in a green shade. After the bath has been practically exhausted, the fiber is taken out, the bath is cooled down to 50 C. and to the bath is added the desired quantity of a mordant dyestuff and of Glauber salt and the necessary quantity of an acid and the tanned Lanital fiber is again immersed therein. The dyeing is then carried out in the usual manner and after chromed under addition of potassium bichromate at the boiling temperature. A dyed fiber possessing smooth touch, high elasticity and resistance to breakwill be obtained.

Example 4 A mixed material consisting of equal parts of wool and of Lanital are treated during 30 minutes in a solution containing 50 grams of chrome alum per litre of water, whereby the treatment is carried out at the boil. After this time the mixed material is hydroextracted, washed with cold water, treated during 1 minute with a solution of ammonia of 0.25 per cent, washed again, hydroextracted and dried. By this tanning operation the properties of the Lanital become so far improved, that it withstands, without decrease of its properties, the long boiling necessary for the dyeing of the mixed material.

Example 5 Lanital yarn is treated during 5 minutes at the boiling temperature with a 9 per cent aqueous solution of chrome chloride in a bath ratio 1:10, whereby a rapid and level wetting-out of the fiber takes place. The fibers are then hydroextracted, well washed with cold water, neutralized with water containing sodium carbonate, washed again, hydroextracted and dried.

If one will dye the material treated in this manner immediately after the tanning, it is no more necessary to neutralize and to dry the yarn, especially in the case where it is intended to dye the material in an acid bath.

Example 6 10 parts of Lanital yarn are boiled during3 minutes in parts of a 10 per cent aqueous chrome fluoride solution, washed, neutralized and washed again. The yarn treated in this manner can be dyed with acid dyestuifs in presence of an acid at the boiling temperature without its fastness to breaking and its elasticitybeing decreased. The dyed yarn possesses the same fastness to washing as the respective dyeing on wool.

Example 7 Lanital yarn is treated at'the boiling temperature and in a bath ratio 1:10 during 15 minutes in a 30% aqueous solution of chrome acetate to which have been added 1-2 grams of a, wetting agent consisting of cocoa fat acid polyglycerides per liter bath. After this treatment the yarn is hydroextracted, washed out and dried.

Example 8 Lanital in loose form is treated during 10 minutes with a boiling 30 per cent aqueous solution of complex sodium chrome oxalate. If it is intended to dye the material tanned in this manner with a mordant dyestuif such as Indochro mine 2R (Colour Index No, 931), it is not necessary to completely wash out the chrome solution, but the material is only hydroextracted and introduced into a die bath containing the dyestuff and the necessary quantity of the chrome mordant and acid. The dyeing is carried out in the usual manner.

Example 9 The tanning operation can sometimes be carried out simultaneously with the dyeing. This is possible in the case where the used dyestufis are not precipitated by the chrome salts or altered in their shade: what happens in the case of many acid dyestuffs, or when mordant dyestuffs, which are developed by the treatment with trivalent chrome compounds, such as Indochromine 2R, are used.

In this latter case one will Work as follows: To 300 parts of a 2 per cent sodium chromoxalate solution there is added the desired quantityv of the Indochromine 2R-solution and the necessary quantity of acetic or formic acid. 10 parts of Lanital yarn are then introduced into this bath, which is heated up to the boiling point hour, and boiled therein during 1 /2 hours. A yarn dyed of a blue shade will be obtained which, in spite of the long boiling period, possesses a much better touch and breakage fastness than a Lanital fiber which has been dyed in the same manner, but only in presence of the quantity of sodium chromoxalate which is necessary for forming the chromium lake of the dyestuif I'ndochromine 2R.

The term tanning as employed in the present specification is not intended to refer to tanning in the sense of converting untanned material into tanned material, but is rather intended to describe what may be termed a mordanting process, i. e. a process analogous to the mordanting of wool in order to prepare 'it for dyeing with chrome colors.

What I claim is:

1. A process for improving water-insoluble, ar-, tificial fibers prepared from solutions of casein, comprising the step of treating the said fibers with a solution of a salt of trivalent chromium fibers, and subjecting the same to a treatment with an acid binding agent.

3. A process for improving water-insoluble, artificial fibers prepared from solutions of casein, comprising the steps of treating the said fibers with a solution of a salt of trivalent chromium at a temperature of at least 0., thereby causin the formation and fixation of a water-insoluble chromium compound in and on the treated fibers, and dyeing the treated fibers with a mordant dyestuff, without eliminating the excess of the chromium salt and of the acid formed.

4. A process for improving water-insoluble, artificial fibers prepared from solutions of casein, comprising the step of treating the said fibers in presence of a suitable dyestuff with a solution of a salt of trivalent chromium at a temperature of at least 50 C., thereby causing the formation and fixation of a water-insoluble chromium compound in and on the treated fibers.

5. A process for improving water-insoluble, artificial fibers prepared from solutions of casein, comprising, the step of treating the said fibers with an aqueou solution of chrome alum at a temperature of 50-100 C.

6. A process for improving water-insoluble, artificial fibers prepared from-solutions of casein,

comprising the step of treating the said fibers with an aqueous solution of chromium chloride at a temperature of 50-100 C.

7. A process for improving Water-insoluble, artificial fibers prepared from solutions of casein, comprising the step of treating the said fibers with an aqueous solution of chromium fluoride at a temperature of 50-100 C.

WALTER .FRIEDRICH TSCHUDIN. 

